Yamaha TRX850 Enthusiasts Forum

ok as the title says, the vacuum pump seals have gone i think. discovered a lot of fuel in one of the vacuum hoses when i did the balance and so will need to replace the vacuum pump.

haveing a bit of trouble finding a seal repair kit then noticed minces ref to an electric pump set up....(hmm like this idea)
mince m8 what is involved with this pump setup?
do i need to replace or mod the fuel tank tap?
if i get an elec setup can i just block up the vacuum line from the tap?

have found the elec pump mince was talking about so that is all good just wanted to see if anyone else has found a repair kit that is under £30, if so i will poss get that. BUT i like the idea of removing vacuum lines that can leak and cause problems in favour of the elec pump.

ideas please people.
many thanks RCT

Er... we don't have a fuel pump in the TRX...?

Replacing a relatively simple vacuum tap with an electric pump seems like more trouble than it's worth & would certainly cost more than 30 pounds.

M.V. wrote:Er... we don't have a fuel pump in the TRX...?

Replacing a relatively simple vacuum tap with an electric pump seems like more trouble than it's worth & would certainly cost more than 30 pounds.

Hang on..whats that apparatus that the lower fuel tap line goes to...[ im not being sarcastic MV]..ive never really thought about the rex having a pump.
Come to think..ive never heard of a problem coming up with the gizmo.....weve got the vacume line to open the fuel tap.....and then there is the other manifold pulse line going to the do-hickey...and then the fuel goes to the carbs....once again..ive never thought about it.
And id be with MV..an electric pump would surelly be problematic.....bzzzzzzzzzzzz

My Haynes manual refers to and shows a picture of a part it calls a 'fuel pump'. I don't know if it is or isn't a fuel pump - a mate of with a TRX thought i was nuts for referring to it as a fuel pump. He started talking about vacuums and stuff an I nodded knowingly

So we DO have a fuel pump?



Interesting...

yes we have a vacuum operated fuel pump.
But perhaps if you have fuel in the vacuum side of the tap, check the tap diaphragms for wear.
Kits are available for both the pump and the tap.
Trx taps are known to leak on the vac side, leading to fuel leakdown in the bores and oil contamination.
Cheers
Fung

well many thanks for the replys chaps, does anyone have a link to the repair kits then?
RCT

rct wrote:well many thanks for the replys chaps, does anyone have a link to the repair kits then?
RCT

Pretty sure ive seen the diaphram replacement kit on e-bay with an international search...a lot of the good stuff is from the UK ..!
Knew a lass with a UK diaphram replacement kit once.. ..but she was an Aussie...should have married that one.!

Hi RCT

If it's a fuel TAP repair kit you want then there are 3 on ebay uk.

You may be able to check if the tap is leaking by taking the tank off and leaving it on a bench to check for any even slight drips or leaks.

I've never seen a PUMP repair kit advertised, so if your problem is the pump then this may be the time to seek an alternative.

I think Minchead's point about replacement is a general vacuum versus electric one, no diaphragm to break, increased flow etc.

I'd start at the tap myself.

Cheers, Andy.

andyaber wrote:Hi RCT

If it's a fuel TAP repair kit you want then there are 3 on ebay uk.

You may be able to check if the tap is leaking by taking the tank off and leaving it on a bench to check for any even slight drips or leaks.

I've never seen a PUMP repair kit advertised, so if your problem is the pump then this may be the time to seek an alternative.

I think Minchead's point about replacement is a general vacuum versus electric one, no diaphragm to break, increased flow etc.
I'd start at the tap myself.

Cheers, Andy.

thanks for the advice dude i am going to go with minces elec pump route, as far as i see it it don't matter if the tap on the tank leaks with the elec pump, as no fuel will get to the carb unless the pump is on.
so all good as i see it, only the cost of the pump and some fuel hose and a bit of jiggory pokery and seh should be leak free i hope.
RCT

Hi RCT

The fuel tap is opened by a vacuum tube from the carbs. If the tap leaks then petrol may be able to leak through this tube directly into the carbs/pot bypassing the pump altogether and filling your engine with petrol regardless of type or condition of pump.

I think I've got that sort of right and no doubt others will be along to explain better or correct me.

If the tap doesn't leak, end of problem.

Cheers, Andy.